It's hot: Porsche Spyder excels on desert test run

A prototype of the 918 Spyder on a desert run. Production will start next year. Porsche expects to make 918 of the cars and charge $854,000 each. (Porsche Cars North America / The New York Times)

When a troupe of Porsche engineers arrived in Las Vegas last month, their cars — prototypes of the 918 Spyder, a supercar that is more than a year from its market debut — barely distracted tourists from their preoccupations. Instead of stopping the show, the two otherworldly supercars slipped unobtrusively into a hotel driveway.

But the engineers were jubilant: A two-week shakedown run, which started in Denver and proceeded through Phoenix on a meandering, blazing-hot route to San Francisco, revealed nothing to imperil the 918 Spyder's scheduled production startup of Sept. 18, 2013.

A plug-in hybrid that combines electric drive and a midmounted gasoline V-8, the 918 Spyder is capable of highly efficient travel (when relying exclusively on battery power) or heroic feats (when the gas and electric power plants fully combine for 795 horsepower).

Only 918 examples will be made; delivery to U.S. customers who have made a $200,000 deposit begins in January 2014, with each car priced at $854,000, not including shipping.

While Porsche is experienced in creating ultrafast cars and knows its way around hybrid powertrains and the production of carbon-fiber chassis, the 918's complexity presents new challenges. The Western road test was intended to verify hot-weather performance, which was reported as satisfactory. The project director, Frank Walliser, and his colleagues also worked on harmonizing the car's myriad systems. The engineers looked for hiccups in drivability that would signal a need for further development of the car's software.

Those who found the 918 Spyder design study so mesmerizing when it was introduced at the 2010 Geneva Motor Show would not be disappointed with the prototypes. Spattered and smudged from the journey up and down mountains and across searing basins, the cars closely resembled that sparkling concept.

Key aspects that remain true include the huge wheels, 20 inches in front and 21 inches at the rear, and a signature swooping line that starts just behind each front wheel. The line continues rearward, opening up to intake scoops that supply radiators, one on each side, that cool the midmounted powertrain.

The 918 Spyder has removable roof panels, similar to those of past 911 Targa models. The roof's pronounced "double-bubble" contours draw straight into a similarly undulant rear cowling. The Geneva car's electric-lime exterior and interior accents survive. And by standing directly in back and staring, as an early critic observed, you can still see the face of Donald Duck.

Evolving to meet practical considerations like crashworthiness, the 918 Spyder has grown by 6 inches, to an overall length of roughly 183 inches. The gasoline engine has expanded, to 4.6 liters (580 horsepower) from the concept car's 3.4 liters. There are three electric motors, one at each front corner and a third integrated with the engine and transmission.

A seven-speed, dual-clutch automatic transmission regulates all this might. To lower the car's center of gravity, the transmission has been flipped upside down, placing the weighty gear clusters closer to the road.

One notable change from the concept car is the deletion of exhaust pipes that emerged through the bodywork just ahead of each rear wheel. Hot gases now exit upward through the rear cowl, with the two pipes looking like ship's funnels.

"The temperature problem in back is very challenging," powertrain engineer Christian Hauck says. "We decided to get the heat as soon as possible out of the back."

According to Walliser, the project is on target to meet its three main goals, which include delivering an evocative design, excelling at hotlaps around the Nürburgring and realizing a fuel-economy equivalent of 70 mpg when the car runs in electric mode. (As an EV, it can go up to 15 miles on power from the 6.8-kilowatt-hour lithium-ion battery with a top speed of 90 mph.)

Questions linger about Porsche's special sports car. Foremost is the daunting task of finishing development work in less than a year. The second question is about the necessity of the hybrid electric drive system. Are the benefits really worth the cost and complication?

Once it was removed from the gaudy surroundings of the Las Vegas Strip, the 918 Spyder showed incomparable zing. Michael Holscher, project manager for research at Porsche, says people reacted generously throughout the team's journey.

"I've never had such positive feedback," Holscher says. "Everybody's happy we made the car. I think we did the right thing."